JP2022119365A - Support and current measurement sensor - Google Patents

Abstract

To stably support a coil for current measurement around an insulating cylinder of a terminal connection portion.SOLUTION: A support 100 includes a flexible ring 101 that is formed in a ring shape along the circumferential direction, and includes a notch 101a extending from the outer circumference to the inner circumference, and a slit 101b extending in the circumferential direction between the outer circumference and the inner circumference, and a plurality of hooks 102 arranged in the circumferential direction on the outer peripheral side of the ring 101 relative to the slit 101b.SELECTED DRAWING: Figure 1

Description

The present invention relates to a support and an amperometric sensor.

A power cable is connected to an electrical device such as a gas-insulated switchgear installed in a power system via a terminal connector (see, for example, Patent Literature 1). A power cable has an inner semiconductor layer, an insulator layer, an outer semiconductor layer, a shield layer and a sheath that are sequentially coated around the outer periphery of a conductor core. The terminal connection part consists of a cylindrical bushing, an adapter, an insulating cylinder and a protective metal tube, which are connected in the axial direction and into which the end of the power cable is inserted, and a conductor connected to the conductor core exposed at the end of the power cable. A pull bar and a stress relief cone wrapped around the power cable within the bushing.

A surge is generated in an electrical device as the electrical device is cut off or charged. A surge is also generated by the influence of lightning, a ground fault, or the like. Surge causes dielectric breakdown and affects the service life of equipment. Therefore, in order to detect the occurrence of a surge, the current flowing through the conductor core of a power cable is observed (see Patent Document 2, for example). A Rogowski coil is used for current measurement. However, simply winding the Rogowski coil around the power cable cannot accurately measure the current flowing through the conductor core of the power cable, especially the excessive current due to surges. This is because the surge component of the current flowing through the conductor core escapes to the shield layer, so it is difficult for the Rogowski coil to capture the magnetic field due to the surge component of the current flowing through the conductor core.

JP 2012-231654 A Japanese Patent Application Laid-Open No. 2007-020301

As described above, the end portion of the power cable is step-stripped inside the terminating portion, and the shield layer is also stripped. Therefore, if a Rogowski coil is wound around the insulating tube of the terminal connection portion, the current flowing through the conductor core of the power cable can be measured using the Rogowski coil. However, there is a problem with fixing the Rogowski coil. In other words, since no protrusions or the like are provided on the outer peripheral surface of the insulating tube of the terminal connection portion, the Rogowski coil wound around the insulating tube cannot be stably supported.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to enable a current measuring coil to be stably supported around an insulating cylinder of a terminal connection portion.

In order to solve the above problems, the support is formed in a ring shape along the circumferential direction and has a notch extending from the outer periphery to the inner periphery, and the A flexible ring having a slit extending in the circumferential direction, and a plurality of hooks arranged in the circumferential direction on the outer peripheral side of the ring from the slit.

Preferably, the ring surrounds a cylindrical adapter that constitutes a terminal connection for connecting a power cable to an electrical device, and is mounted on a flange provided at the lower end of the outer circumference of the adapter, A plurality of bolt heads arranged in the circumferential direction on the flange are inserted into the slits, and the hooks hang down from the outer periphery of the flange and surround an insulating cylinder connected to the bottom of the adapter. A Rogowski coil wound around the insulating tube is hung on the hook.

In order to solve the above problems, a cylindrical adapter that constitutes a terminal connection part for connecting a power cable to an electrical device and an insulating cylinder that is connected below it extend vertically inside the adapter, and the adapter And a current measurement sensor for measuring the current of the power cable from which the shield layer is stripped inside the insulating cylinder, comprising a Rogowski coil and a support, wherein the support extends along the circumferential direction A flexible ring formed in a ring shape and having a notch extending from an outer periphery to an inner periphery and having a slit extending in the circumferential direction between the outer periphery and the inner periphery; and the ring rather than the slit. and a plurality of hooks arranged in the circumferential direction on the outer peripheral side of the adapter, and the ring surrounds the adapter and is placed on a flange provided at the lower end of the outer periphery of the adapter, and the slit is inserted with a plurality of bolt heads arranged in the circumferential direction on the flange, the hooks hang down from the outer circumference of the flange and are positioned around the insulating cylinder, and the hooks: The Rogowski coil wound around the insulating cylinder is hung.

According to the above, since the notch extends from the outer circumference to the inner circumference of the ring, the adapter can be surrounded by the ring. When the ring is placed on the flange, the bolt head is inserted into the slit, so the ring sits well on the flange. A plurality of hooks are provided on such a ring in the circumferential direction, and the coil wound around the insulating tube is hooked on these hooks, so that the coil can be stably supported around the insulating tube.

According to the present invention, the coil can be stably supported around the insulating cylinder.

FIG. 3 is a perspective view of a support and Rogowski coil; FIG. 10 is a perspective view showing how the support and the Rogowski coil are used; FIG. 4 is a partial cross-sectional view of a termination connection;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various technically preferable limitations are attached to the embodiments described below for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[Summary of Usage of Support Tool and Rogowski Coil]
FIG. 1 is a perspective view of support 100 and Rogowski coil 120. FIG. FIG. 2 is a perspective view showing how the support 100 and the Rogowski coil 120 are used. As shown in FIG. 2 , the support 100 is attached to the terminal connection portion 1 of the power cable 10 , and the Rogowski coil 120 is supported around the terminal connection portion 1 of the power cable 10 using the support 100 . Then, the Rogowski coil 120 is used to measure the current of the power cable 10 inside the terminal connection portion 1 . First, the terminal connector 1 and the power cable 10 will be described with reference to FIG. In the following description, the direction from top to bottom is the direction in which gravity acts.

[Terminal connection and power cable]
FIG. 3 is a partial cross-sectional view of the terminal connection portion 1 of the power cable 10. As shown in FIG.
The terminal connector 1 connects an end 11 of the power cable 10 to a power device such as a gas insulated switchgear (GIS). The end portion 11 of the power cable 10 refers to a portion that has undergone a step stripping process as described later.
The power equipment has an upper case and a lower inspection room 3 . The interior space of the case is separated from the inspection chamber 3 by the bottom plate 2 of the case. The internal space of the case is filled with sulfur hexafluoride gas, which has excellent electrical insulation.
The terminal connection part 1 is passed through a communication hole 2a formed in the bottom plate 2, and the terminal connection part 1 is connected so that the upper part of the terminal connection part 1 is positioned in the case and the lower part of the terminal connection part 1 is positioned in the inspection room 3. A part 1 is installed in a power device. Note that the bottom plate 2 is grounded.

The power cable 10 is a CV cable. The power cable 10 has a conductor core 12 , an inner semiconductor layer (not shown), an insulator layer 13 , an outer semiconductor layer 14 , a shield layer 15 and a sheath 16 that are sequentially coated on the outer periphery of the conductor core 12 . Here, as described above, the end portion 11 of the power cable 10 is step-stripped. Specifically, the sheath 16, the shield layer 15, and the outer semiconductor layer 14 are exposed in order toward the end of the power cable 10 so that the sheath 16, the shield layer 15, the outer semiconductor layer 14, the insulator layer 13, and the conductor core 12 are exposed. , the insulator layer 13 and the inner semiconductor layers are stripped. The power cable 10 shown in FIG. 3 has one conductor core 12, but instead of this, a multi-core power cable having a plurality of conductor cores may be employed.

The terminal connection portion 1 has a conductor pull-out rod 20, a bushing 30, a stress relief cone 40, a pressing device 50, an adapter 60, an insulating cylinder 70, and a protective metal tube 80.

The bushing 30, the adapter 60, the insulating tube 70, and the protective metal tube 80 are cylindrical bodies around the axis with the vertical direction as the axial direction. The upper and lower ends of the bushing 30, the adapter 60, the insulating cylinder 70 and the protective metal tube 80 are open. The bushing 30 and the insulating cylinder 70 are electrically insulating, and the adapter 60 and the protective metal tube 80 are electrically conductive. The bushing 30, the adapter 60, the insulating cylinder 70, and the protective metal tube 80 are connected from above in this order in the axial direction. The direction around the axis of the bushing 30, the adapter 60, the insulating tube 70 and the protective metal tube 80 is called the circumferential direction.

A flange 31 is provided at the lower end of the outer circumference of the bushing 30 . A flange 61 is also provided at the upper end of the outer circumference of the adapter 60 . These flanges 31 and 61 are fixed to each other by bolts or the like. Thereby, the lower end of bushing 30 is connected to the upper end of adapter 60 . A flange 61 of the adapter 60 is fixed on the bottom plate 2 around the communicating hole 2a of the bottom plate 2, and the adapter 60 protrudes downward from the bottom plate 2 through the communicating hole 2a. Note that the adapter 60 is grounded via the bottom plate 2 .

A flange 62 is provided at the lower end of the outer circumference of the adapter 60 . The flange 62 has through holes arranged in a circumferential direction. A bolt 63 is helically attached to the insulating tube 70 through a through hole in the flange 62 . That is, the flange 62 is fastened to the upper end of the insulating cylinder 70 with bolts 63 . The heads of the bolts 63 are circumferentially spaced on the flange 62 .

The lower end of the insulating tube 70 is fastened to a flange 81 provided at the upper end of the protective metal tube 80 with bolts (not shown) arranged in the circumferential direction. Protective metal tube 80 is grounded.

The end portion 11 of the power cable 10 is inserted into the protective metal tube 80 , the insulating tube 70 , the adapter 60 and the bushing 30 from below the protective metal tube 80 . A protective tape 82 is wrapped around the protective metal tube 80 and the power cable 10 near the opening at the lower end of the protective metal tube 80 . A protective tape 82 seals the opening at the lower end of the protective metal tube 80 . The shield layer 15 of the power cable 10 is stripped off inside and above the insulating tube 70 to expose the portion inside the shield layer 15 . Therefore, the current of the power cable 10 can be measured using the Rogowski coil 120 wound around the insulating tube 70 as shown in FIG. The shield layer 15 is grounded via a protective metal tube 80. As shown in FIG.

As shown in FIG. 1, the conductor pull-out rod 20 protrudes upward from the inside of the bushing 30 through an opening at the upper end of the bushing 30 and is fixed to the upper end of the bushing 30 with a fastener 21. As shown in FIG. Inside the bushing 30 , the conductor pull rod 20 is connected to the exposed conductor core 12 of the power cable 10 .

The stress relief cone 40 is fitted in the bushing 30 and sheathed on the exposed insulator layer 13 of the power cable 10 . The stress relief cone 40 is pushed upward by a pressing device 50 provided inside the bushing 30 , the adapter 60 , the insulating cylinder 70 and the protective metal tube 80 to press against the cone surface on the inner circumference of the bushing 30 .

[Support]
The support 100 will be described with reference to FIGS. 1 and 2. FIG.
A support 100 comprises a ring 101 and a plurality of hooks 102 .

The ring 101 is a flexible ring-shaped member extending along the circumferential direction, and more specifically, a sheet material or thin plate material having a thin thickness in the axial direction. The ring 101 is made of, for example, a rubber elastic body. The ring 101 is C-shaped by having a notch 101a extending from the outer periphery of the ring 101 to the inner periphery of the ring 101 . Since the ring 101 is flexible, the notch 101a can be expanded circumferentially and axially. 3 can be passed through the notch 101a, and the ring 101 can be installed so as to surround the adapter 60 as shown in FIG.

A C-shaped slit 101b extending in the circumferential direction is formed between the outer circumference and the inner circumference of the ring 101 so as to pass through the ring 101 in the thickness direction. When ring 101 is laid on flange 62 as shown in FIG. 2, the head of bolt 63 is inserted into slit 101b. Therefore, the ring 101 sits well on the flange 62 . In addition, the ring 101 does not unexpectedly move greatly in the circumferential direction due to the head of any of the bolts 63 coming into contact with the circumferential end of the slit 101b.

A plurality of hooks 102 are provided on the ring 101 on the outer peripheral side of the ring 101 relative to the slit 101b. Specifically, these hooks 102 are provided on the outer circumference of the ring 101 at intervals in the circumferential direction. These hook 102 and ring 101 are integrally formed. A hook 102 extends axially from the outer circumference of the ring 101 , and the tip of the hook 102 is bent outward in the radial direction of the ring 101 and folded back toward the ring 101 .

When the ring 101 surrounds the adapter 60 on the flange 62 as shown in FIG. Note that the hook 102 may contact the outer peripheral surface of the insulating cylinder 70 .

[Rogowski coil]
The Rogowski coil 120 has an air core winding (not shown) and a return wire (not shown) housed in a sheath 121 . Both ends of the Rogowski coil 120 are connected by connectors 122 to form the Rogowski coil 120 into a ring shape. One end of Rogowski coil 120 can be removed from connector 122 .

This Rogowski coil 120 is wound around the insulating tube 70 and hung on the hook 102 . Rogowski coil 120 generates an induced electromotive force at a level corresponding to the current level of power cable 10 . The Rogowski coil 120 is connected to an integrator via an output cable 123, and a voltage signal representing the level of the induced electromotive force in the Rogowski coil 120 is integrated by the integrator. The level of the integrator output signal is proportional to the level of current in power cable 10 . The output signal of the integrator is input to a display or recording device or both. A display displays the value of the measured current based on the output signal of the integrator. A recording device records the value of the measured current based on the output signal of the integrator.

Here, a combination of the Rogowski coil 120 and the support 100, that is, a structure in which the ring-shaped Rogowski coil 120 is hung on the hook 102 of the support 100 is called a current measurement sensor.

[Current measurement method using support and Rogowski coil]
The notch 101a of the ring 101 is widened by deforming the ring 101. - 特許庁The adapter 60 is passed through the notch 101 a and the adapter 60 is surrounded by the ring 101 . Then, the ring 101 is placed on the flange 62 while the hooks 102 are positioned outside the outer circumference of the flange 62 , and the hooks 102 are suspended from the flange 62 . Then, the insulating cylinder 70 is surrounded by these hooks 102 . When mounting the ring 101 on the flange 62, the head of the bolt 63 is inserted into the slit 101b.

One end of Rogowski coil 120 is removed from connector 122 . The Rogowski coil 120 is wound around the insulating tube 70 and one end of the Rogowski coil 120 is connected to the connector 122 . A ring-shaped Rogowski coil 120 is hung on the hook 102 . Also, the shape of the Rogowski coil 120 is adjusted to make the shape of the Rogowski coil 120 circular.

After the Rogowski coil 120 is supported around the insulating tube 70 by the support 100 as described above, the current of the power cable 10 is measured using the Rogowski coil 120 . After the current measurement is completed, one end of the Rogowski coil 120 is removed from the connector 122 and the Rogowski coil 120 is removed from the hook 102 . Next, the ring 101 is lifted from the flange 62 , the adapter 60 is passed through the notch 101 a of the ring 101 , and the ring 101 is removed from around the adapter 60 .

[advantageous effect]
(1) The support 100 is attached to the terminal connection portion 1 using the outer shape of the terminal connection portion 1 . That is, the ring 101 is wound around the cylindrical adapter 60 and placed on the flange 62 , and the head of the bolt 63 is inserted into the slit 101 b of the ring 101 . Therefore, the Rogowski coil 120 can be supported around the insulating tube 70 using the support 100 without processing the outer surface of the terminal connection portion 1 .

(2) A plurality of hooks 102 hang down from the flange 62, the bent portions at the tips of the hooks 102 are positioned around the insulating tube 70, and the Rogowski coil 120 wound around the insulating tube 70 is attached to these hooks 102. is hung. Therefore, the Rogowski coil 120 can be stably supported around the insulating tube 70 without attaching the Rogowski coil 120 to the outer peripheral surface of the insulating tube 70 with an adhesive tape or the like.

(3) Since the ring 101 surrounds the adapter 60, the ring 101, the adapter 60 and the power cable 10 can be arranged concentrically. A plurality of hooks 102 are provided on such a ring 101 in the circumferential direction, and Rogowski coils 120 are hooked on these hooks 102 . Therefore, the row of hooks 102, the Rogowski coil 120 and the power cable 10 can be arranged concentrically. Then, the distance from the Rogowski coil 120 to the center of the power cable 10 can be made uniform, so that the current in the conductor core 12 can be stably and accurately measured.

(4) A slit 101b is formed in the ring 101, and the head of the bolt 63 is inserted into the slit 101b. Therefore, the ring 101 is stably placed on the flange 62 , and deformation and displacement of the ring 101 due to the weight of the Rogowski coil 120 can be suppressed. Therefore, Rogowski coil 120 can be stably supported around insulating tube 70 .

(5) The slit 101b extends in the circumferential direction and forms a C shape. Therefore, regardless of the number of bolts 63, the heads of these bolts 63 can be inserted into the slits 101b.

(6) The ring 101 has a notch 101a to form a C shape. Therefore, the ring 101 can be attached around the adapter 60 and the ring 101 can be removed from around the adapter 60 without disassembling the terminal connection portion 1 . Thus, the support 100 can be used for other termination connections as well.

(7) Since the ring 101 is flexible, the ring 101 can be folded. Therefore, the support 100 can be compactly stored.

(8) Since the ring 101 and the hook 102 are integrally formed, the support 100 is easy to handle.

DESCRIPTION OF SYMBOLS 1... Terminal connection part 60... Adapter 61... Flange 63... Bolt 70... Insulating tube 100... Support tool 101... Ring 101a... Notch 101b... Slit 102... Hook 120... Rogowski coil

Claims (3)

a flexible ring formed in a ring shape along the circumferential direction, having a notch extending from the outer circumference to the inner circumference, and having a slit extending in the circumferential direction between the outer circumference and the inner circumference;
and a plurality of hooks arranged in the circumferential direction on the outer peripheral side of the ring relative to the slit. The ring surrounds a cylindrical adapter that constitutes a terminal connection portion for connecting a power cable to an electrical device, and is placed on a flange provided at the lower end of the outer periphery of the adapter,
A plurality of bolt heads arranged in the circumferential direction are inserted into the slit,
The hook hangs from the outer periphery of the flange and is positioned around an insulating tube connected to the bottom of the adapter,
2. A support according to claim 1, wherein said hook is hooked with a Rogowski coil wound around said insulating tube. A cylindrical adapter that constitutes a terminal connection part for connecting a power cable to an electrical device, and a shield layer that extends vertically inside an insulating tube connected below the adapter and the insulating tube, and inside the adapter and the insulating tube A current measurement sensor that measures the current of the stripped power cable,
comprising a Rogowski coil and a support,
The support is
a flexible ring formed in a ring shape along the circumferential direction, having a notch extending from the outer circumference to the inner circumference, and having a slit extending in the circumferential direction between the outer circumference and the inner circumference;
a plurality of hooks arranged in the circumferential direction on the outer peripheral side of the ring relative to the slit,
The ring surrounds the adapter and rests on a flange provided at the lower end of the outer circumference of the adapter,
a plurality of bolt heads arranged in the circumferential direction on the flange are inserted into the slit;
The hook hangs down from the outer periphery of the flange and is positioned around the insulating cylinder,
A current measuring sensor in which the Rogowski coil wound around the insulating cylinder is hung on the hook.

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